Twist drill sharpener



c.. FW i945, -LBANNER 2,408,544

TWIST DRILL SHARPENER Filed Jan. l, 1945 Patented ct. 1946 UNT-ED STATES PATENT OFFICE;-

- I f Y 2,408,544

d g T'W'Isr 'DRILL SHARPENER- Joseph Banner, Los Angeles, Calif. Application January 1, 1945, serial No. 570,933

, 1 .Y This invention relates to and has for an object the vprovision of a fixture for honing Ytwist drills, particularly of the smaller sizes,so that the op- ,positel'y inclined portions of the drill may be disposed, one after the other, in a plane paralleling with an angular surface of thexture, andthe drill then locked in the iixture in a suitable position for honing the end portions of the drill.

l I am aware that flxtureshave heretofore been used for supporting drills in position relative to a grinding wheel, but my ixture isdesigned to supporta drill in position whereby the drill end may be honed and sharpened at a'requisite angle.

An object is also to provide la xture with a hole of square or rectangular cross section extending longitudinally therethrough in which a twistdrill may b-e detachably held in one of the angular corners of the hole during a honing operation, said hole being preferably of sufficient area to accommodate a numberv of drills of different sizes.

y A further object is to provide a transverse slot in the fixture body in which a clamp is rotatable to an extent of 180 degrees, so that when a drill is 'inserted with one of the angular lips thereof extended slightly upwardly of anangular endv surface of the body the drill may be set in the may not rotate during a honing operation. However, upon completion of a honing operation on one of theangular end lips of the drill,the drill may be loos'ened'in the body so that it may rota'tewith the clamp to an extent of 180 degrees, and thereby position the other angular lip of the drillrelative to the angular end surface of the body. Thus, it will be observed thatthe two angular end portions of the drill are,one after the other, capable of beingr honed to an appropriate angle' and degree of sharpness by merely rotating the drill in the body, after whichthe drill is removed from the body and another may be inserted of the same or different size.

I have shown a preferred embodiment of my linvention in the accompanying drawing in which:

Fig. 1 is a top plan view; Fig. y2 is a side elevation partly in section; Fig. 3 is a sectional elevation on line 3-3 of Fig. l and 5 claims. (o1. isi-219) B is adapted to be adjustably mounted in the slot l for rotation to an extent of 180 degrees, and said clamp has a square hole 4 therethrough of the same size, and which registers with the hole 2 in the body A. Thus, as shown in Fig. 2 a drill D may be extended through the holes 2 and 2a of the body and the hole 4 of the clamp B to a desired extent preparatory to a honing operation. It will be noted that clamp B has a set screw 5 threaded thereinto and provided with a knurled head ii 'so' that drill D may be xedly held in the clamp. Also -body A has a similar set screw 'l with a lznurled head 8 near the forward end of the body which is threaded into the body and is adapted to engage drill D. By reference to Fig. 3 it will be seen that the slot I is closed only at one side of the body, leaving a wall 9 underlying the clamp B. 'It will also be noted that clamp B has parallel opposite sides I0 and Il which are adapted to bear against the inner surface .l2 of wall 9 for limiting the rotation of the clamp B on' the body to an exact extent of 180 degrees.

In Fig. 3 I have shown the clamp B in full lines in one position and in dotted lines in an adjusted posi-tion to an extent of 180 degrees. Now, by reie'rence to Fig. 4 it will be noted that the drill D has angular lips i3 and 'I 4, which are disposed at corresponding angles (291/2 degrees) and the usual peripheral ilutes I5.

Now, referring to Fig. 2 it will be noted that the forwardend IS of body A is disposed at an angle corresponding to the angle of the lips I3 and la of the drill. Also, as shown in Fig. l, the end surface I6 is tapered backwardly, as at l1, merely for convenience in moving a hone over the drill end.

Now, in operation with a drill D inserted in the fixture', as shown in Fig. `2, one of the lips I4 will be 'disposed substantially at the same angleas thesurface `liof the body and but very slightly [extended therefrom, the drill having previously been locked in clamp B by tightening screw r5, and then locked in body A by tightening screw 1, so that during the honing operation the drill lip is always disposed at a proper angle. Following the sharpening of one of the drill lips screw 1 is loosened and clamp B is turned to an extent of 180 degrees on the body, as indicated by broken lines in Fig. 3, so as to properly position the second drill lip relative to the honing surface I6. Thus, one of the sides I0 or ll of the clamp Bis always engaged with the inner side I2 of kwall 9 during the honing operation.

is properly indexed with the honing surface by the adjustment of the clamp B.

Preferably in the use of my improved honing xture for sharpening drills of sizes from l to 80 it is desirable to provide four fixtures. of different size corresponding to the difference in diameter of the drills and in length of the drills, Y

and the holes 2 and 2a in the fixture and 4 in' the clamp B Will be of such size as to accommodate approximately twenty drills of consecutive sizes, as from 80 to 60, 60 to 40, l0 to 20 and 20 to l. Additional xtures for drills of a larger size than those mentioned will be correspondingly larger in diameter.

I claim:

1. A drill sharpening fixture comprising: a body formed with a transverse recess and a longitudinal hole extended entirely therethrough and open at opposite ends of the body, a clamping member mounted in the recess of the body and rotatable on the body to an extent of one hundred eighty degrees in a transverse plane and also having a hole therethrough in registration with the hole in the body for receiving and supporting a drill in sharpening position, said clamping member being rotatable on the body about the axis of and with the supported drill, and separate means for locking the clamping member on the drill and the drill on the body so that when a cutting lip of the drill is positioned relative to a surface of said body the drill may be held in a xed position during a sharpening operation.

2. A drill sharpening fixture comprising: a body formed with a transverse recess and a longitudinal hole extended entirely therethrough and open at opposite ends of the body, a clamping member rotatable in the recess of the body to an extent of one hundred eighty degrees in a transverse plane and also having a hole therethrough in registration with the hole in the body for receiving and supporting a drill in sharpening position, said clamping member being rotatable on the body about the axis of and with the supported drill, and separate means for locking the clamping member on the drill and the drill on the body so that when a cutting lip of the drill is positioned relative to a surface of said body the drill may be held in a iixed position during a sharpening operation, an end of said body being disposed at an acute angle relative to the axis of the drill and in substantial parallelism with a cutting lip of the drill.

3. A drill sharpening xture comprising: an elongated body having a hole of rectangular cross section longitudinally formed therein and open at both ends of the body for receiving and supporting drills of diiierent diameter in a sharpening operation, an end of said body having a surface disposed at an angle corresponding to that of the cutting lips of a supported drill, said body having a transverse slot therein, a clamping member rotatable in said slot and having a, drill receiving hole therein adapted 'for registration with the hole in the body, means, for locking said clamping member to said drill against longitudinal movement of the drill, and means for locking said drill to the body for preventing rotation of the drill and clamping member during a sharpening operation.

4. A drill sharpening iixture comprising: an elongated body having a hole of rectangular cross section longitudinally formed therein and open at both ends of the body for receiving and supporting drills of different diameter in a sharpening operation, an end of said body having a surface disposed at an angle corresponding to that of the cutting lips of .a supported drill, said body having a transverse slot therein, a clamping member rotatable in said slot and having a drill receiving hole therein adapted for registration with the hole in the body, means for locking said clamping member to said drill against longitudinal movement of the drill, and means for locking said drill to the body lfor preventing rotation of the drill and clamping member during a sharpening operation, and means on the body for limiting the rotation of the clamping member to an extent defined by the spacing of the cutting lips on the drill to be sharpened.

5. A drill sharpening fixture comprising: an elongated body having a hole of rectangular cross section longitudinally formed therein and open at both ends of the body for receiving and supporting drills of different diameter in a sharpening operation, an end of said body having a surface disposed at an angle corresponding to that of the cutting lips of a supported drill, said body having a transverse 'slot therein, a clamping member rotatable in said slot and having a drill receiving hole'therein adapted for registration with the holein the body,means -for locking said clamping member to said drill against longitudinal movement of the drill, and means for locking said drill to the body for preventing rotation of the drill and clamping member during a sharpeningv operation, and means on the body for limiting the rotation of the clamping member to an extent defined by the spacing of thecutting lips on the'drill to be sharpened, said clamping member being rotatable about the axis of the supported drill,

JOSEPH BANNER. 

